Highway barrier



Nov. 4, 1969 T. E. mm

HIGHWAY BARRIER Filed Sept. 30. 1968 FIGI IN VENTOR Tea E. Thompson FIGS United States Patent M 3,476,362 HIGHWAY BARRIER Ted E. Thompson, Center Valley, Pa., assignor to Bethlehem Steel Corporation, a corporation of Delaware Filed Sept. 30, 1968, Ser. No. 763,720 Int. Cl. E01f /00 US. Cl. 25613.1 5 Claims ABSTRACT OF THE DISCLOSURE A- strong beam-weak post highway barrier comprising an elongated box-shaped guard rail connected to supporting posts with plates which are secured to the tops of the posts and mechanically fastened to the bottom wall of the guard rail. Each plate has a pair of open-ended slots located at its opposite ends and lying parallel to the guard rail. The slots coincide with two elongated apertures spaced along the rail and formed in its bottom wall. The adjacent portions of these apertures are sized smaller than their portions which are farthest apart. A pair of mechanical fasteners, passing through the coinciding slots and elongated apertures, connect each post to the rail. However, the parts of the fasteners which are located within the rail are smaller than the large portions of the apertures. With this arrangement each rail-to-post connection is readily disengageable. Vehicle impact on a post in a direction longitudinally along the barrier causes one of the fasteners to slip downwardly out of the large portion of an elongated aperture, while the other fastener emerges from its open-ended slot.

An easily erected barrier may be obtained by forming the elongated box-shaped rail with upper and lower channel members having overlapping portions at both sides of the rail. The channel members are held together by nuts secured to the inner surfaces of the side walls of the rail, and by bolts which pass through preformed holes in the overlapping portions of the channel members and engage the'nuts.

Background of the invention This invention relates to highway barriers and, more particularly, to a strong rail-weak post highway barrier.

The strong rail-weak post barrier is a recent development in highway barrier design. The high strength of the rail prevents pocketing, i.e., the formation of large deformations in the rail which may snag the impacting vehicle. The weak posts are designed to fail and collapse rather than snag the wheels of a vehicle impacting the posts in a direction generally longitudinally along the barrier. The rail-to-post connections disengage under such longitudinal impact and allow the rail to remain at an elevation where it can effectively stop and safely direct the vehicle. Yet, the connections are sufficiently strong to withstand vehicle impact in a direction lateral to the barrier and thus aid in preventing the vehicle from leaving the area adjoining the highway.

Different embodiments of the strong beam-weak post highway barrier have been tried. However, field erection of these barriers has been relatively costly because the rails have consisted of lengths of whole tubes which require equipment when lifted into place.

In addition, since the rail-to-post connections must be disengageable, these prior barriers provided loose attach- Patented Nov. 4, 1969 ments between the rail and posts. These attachments, unable to keep the individual lengths of rail aligned, gave any substantial length of barrier at ragged appearance.

Summary of the invention My invention relates to an easily erected strong rail- Weak post highway barrier having posts which readily disengage from the rail when impacted in a direction longitudinally along the barrier.

The rail is an elongated box-shaped member connected to each post by fasteners extending through two elongated apertures spaced along its bottom wall. Each pair of elongated apertures lies parallel to the rail and the apertures adjacent portions are sized smaller than their portions which are farthest apart. Open-ended slots contained in opposite ends of a plate secured to the top of each post coincide with, and lie parallel to, the small portions of each pair of elongated apertures. Mechanical fasteners connect the barrier together by passing through the small portions of the apertures and coinciding slots. That part of each of these fasteners which is located within the rail is smaller than the large portion, although larger than the small portion, of the aperture through which it passes. This feature allows one of the fasteners to drop downwardly out of the rail when a post bends at the ground under longitudinal impact. The remaining fastener at the impacted post is freed by emerging from the open-ended slot in which it was placed. While the rail-to-post connection is readily disengageable upon longitudinal impact, the fasteners passing through the slots in the plates and small portions of the elongated aperture tightly connect the barrier together. Thus, the separate lengths of the rail are kept aligned and a ragged appearance is prevented.

By forming the rail with upper and lower channel members having overlapping portions at both sides of the rail, and by securing nuts to the inner surfaces of the channel members at the sides of the rail, a barrier is produced which may be easily erected. The lower channel member may be initially supported on and connected to the plates at the top of the posts. Thereafter, the upper channel member may be set in place and secured to the lower channel member by bolts which pass through preformed holes in the Overlapping portions of the channel members and engage the nuts within the rail. Since the heavy rail is formed by two members, it need not be lifted into place at once. Each channel member may be manually placed and lifting equipment is not required.

The channel members may be cold rolled sections. The feasibility of this method of rail manufacture provides my highway barrier with an additional economic advantage over previously used barriers having tubes as their rails.

In addition, after the barrier has been impacted, a rail formed by channel members is easier to repair than one which consists of a tube.

Brief description of the drawing FIGURE 1 is a side elevation of a highway barrier embodying my invention.

FIGURE 2 is an enlarged section taken along line 2-2 of FIGURE 1.

FIGURES 1 and 2 show a highway barrier having an elongated box-shaped guard rail 1 supported at a fixed elevation by a series of upright posts 2 whose lower portions are embedded in the ground. Since the barrier is a strong beam-weak post design, the posts are structurally weaker than the rail and will bend relatively easily at the ground when impacted in a direction generally longitudinally along the barrier. However, it is desirable that the barrier resist, and contain within the area adjacent the highway, a vehicle impacting in a direction essentially lateral to the barrier. The posts are, therefore, arranged with their flanges parallel to the highway. Additionally, a plate 3, also arranged parallel to the highway is welded to each post below the ground. These plates 3 help the barrier to resist lateral impact by providing suflicient bearing surface between the posts and the soil.

As shown in FIGURE 2, the guard rail 1 is made up of upper and lower channel members, 1a and 1b, which overlap at both sides of the rail. The lower channel member forms the bottom wall and lower parts of the side walls of the rail, the upper channel member forms the top wall and upper parts of the side walls. Holes 4 are formed in the overlapping portions and nuts 5 are secured to the inner surfaces of the channel members at the rails side walls. Each of these nuts is aligned with a hole 4 formed in the side wall of the rail to which it is secured. The channel members are held together by bolts 6 which pass through holes 4 and engage the nuts 5. A preferred means of securing the nuts 5 to the inner surfaces of the channel members is a nut retainer of the type disclosed in FIGS. 3 and 4 of US. Patent No. 2,391,046 issued to G. A. Tinnerman on Dec. 18, 1945.

As illustrated in FIGURES 1 and 2, the side walls of the guard rail 1 have longitudinal corrugations forming a trough arranged midway between the rails top and bottom. To avoid snagging an impacting vehicle, the heads of bolts are located within these troughs. The troughs also create a more pleasing appearance and stiffen the rails side walls which, of course, is desirable in a strong rail-weak post highway barrier.

Where the posts supporting the rail are located at the center of the rails width, a dimension of at least twelve inches in width is preferred. This provides suflicient clearance between the posts and an impacting vehicle which only glances the rail. Unnecessary damage to both the vehicle and posts is thereby prevented.

Welded to the top of each post 2 is a horizontal plate 7 which lies parallel and adjacent to the bottom wall of the rail. The barrier is connected together by fastening the rail to each plate 7 with two bolts 8 engaging nuts 9. During erection of the barrier in the field, the posts 2 having plates 7 secured to their tops are embedded in the ground. Nuts 5 are secured to the inner surfaces of the channel members sides. A length of the lower channel member 16 is then placed on plates 7 and spans a plurality of posts 2. Bolts 8 and nuts 9 are used to join this length to plates 7. A length of the upper channel member 1a is then placed on the lower channel member and bolts 6 fasten the two together.

In accordance with strong rail-weak post barrier design, the connections between the rail and the plates secured to the posts are disengageable when the posts are impacted from a longitudinal direction. As illustrated in FIGURE 3, each plate 7 has a pair of open-ended slots 10 which lie parallel to the rail and whose open ends are located at opposite ends of the plate. In the bottom wall of the rail 1 are formed a pair of elongated apertures 11 which lie parallel to and coincide with the slots 10 in plate 7. The elongated apertures 11 are keyhole shaped, each one having its portion nearest the other aperture smaller than its portions farthest from it. Bolts 8 pass through the small portions of these elongated apertures 11 in the bottom wall of the rail and through the open ended slots 10 in plate 7 when connecting the rail and plate together. However the heads of bolts 8 are sized smaller than the large portions of the elongated apertures 11 although larger than their small portions. With this feature bolts 8 tightly fasten the plate 7 to the rail 1 and thus keep the individual lengths of rail aligned.

Under longitudinal impact the post bends at the ground and carries the plate 7, fixed to its top, downwardly and away from the vehicle. This movement of plate 7 pulls the bolt 8 located above the non-impacted side of the post out of the large portion of the elongated aperture 11 in the bottom wall 1b of rail 1. The 'bolt 8 located above the impacted side of the'post comes out of its open-ended slot 10 in plate 7 as the post'and plate are moved. Thus, the rail is left at an elevation where it can direct the impacting vehicle and the weak post, allowed to collapse, cannot snag the vehicles wheels.

Since the slots 10 and apertures 11 are symmetrically arranged on both sides of the posts, the barrier may be used as a'median barrier which isimpacted from both longitudinal directions. Of course, it may also be used as a shoulder barrier on either side of the highway. I

FIGURE 4 shows a splice member 12 which is used to join together two lengths of the elongated box-shaped guard rail 1 as shown in FIGURE 1. Splice member 12 is also an elongated box-shape but ha a portion removed from its bottom wall. One end of the splice member 12 lies within one length of the guard rail, while its other end lies within an adjoining length of the rail.

At the splice, the guard rail is formed in much the same manner as is the rest of the rail. Holes 4, located in the side walls of the rail, pass through the overlapped portions of upper and lower channel members, 1a and 1b, and the side walls of splice member 12. Nuts 5 are secured to the inner surfaces of the side walls of splice member 12 and bolts 6 pass through holes 4 and engage the nuts 5.

During field erection of the barrier, splice member 12, containing nuts 5, is placed within two adjoining lower channel member lengths 1b after they are secured to plates 7. Two adjoining upper channel member lengths 1a are then placed over the splice member 12 and bolts 6 secure the rail together by engaging nuts 5. To strengthen the rail in this area, a plurality of bolts should be used on. both sides of the splice.

I claim:

1. A highway barrier comprising:

(a) an elongated box-shaped guard rail having a bottom wall which contains a pair of elongated apertures extending parallel to and spaced along said rail, each of the elongated apertures having its portion nearest the other aperture smaller than its portion farthest from the other aperture;

(b) a post, structurally weaker than said rail, located under and supporting said rail, said post being readily bendable upon impact in a direction longitudinally along the barrier;

(c) a plate secured to the top of said post and lying adjacent and parallel to the bottom wall of said rail, each of two opposite ends of said plate having an open-ended slot lying parallel to and coinciding with the small portion of one of the elongated apertures in the bottom wall of said rail;

(d) a pair of mechanical fasteners for securing said rail to said plate, said fasteners passing through the small portions of the apertures in the bottom wall of said rail and the slots in said plate, the part of each of said fasteners located within said rail being smaller than the large portion although larger than the small portion of the aperture through which said fastener passes.

2. The highway barrier as recited in claim 1 wherein said rail comprises:

(e) a lower channel member forming the bottom wall and lower parts of the side walls of said rail;

(f) an upper channel member formingthe top wall and upper parts of the side walls of said rails, portions of said upper channel members overlapping portions of said lower channel members at both sides of said rail, both side walls of said rail having holes at the overlapping portions;

(g) a plurality of nuts secured to the inner surfaces of at least one of the channel members, and aligned with the holes in side walls of said rail;

(h) a plurality of bolts passing through the holes in the side walls of said rail and engaging said nuts.

3. The highway barrier as recited in claim 2 wherein each of said nuts is secured to the side wall of said rail which contains the hole with which said nut is aligned.

4. The highway barrier as recited in claim 3 wherein said elongated apertures are keyhole shaped and are arranged along a line in the center of said rails width.

5. The highway barrier as recited in claim 4 wherein the side walls of said rail have longitudinal corrugations forming a trough arranged midway between the top and bottom of said rail, the heads of said bolts which pass through the side walls of said rail being located within the troughs.

References Cited UNITED STATES PATENTS 2,004,026 6/1935 Wooten 256l3.1

2,927,513 3/1960 Dove 256-13.1

3,114,303 12/1963 Oberbach 94-1.5

3,314,658 4/1967 Shoemaker 25613.1

FOREIGN PATENTS 1,302,993 7/ 1962 France.

DENNIS L. TAYLOR, Primary Examiner 

